cbuffer PerFrameBuffer {
  matrix worldMatrix;
  matrix viewMatrix;
  matrix projectionMatrix;
};

struct VertexInputType {
    float4 position : POSITION;
    float2 tex : TEXCOORD0;
};

struct PixelInputType {
    float4 position : SV_POSITION;
    float2 tex : TEXCOORD0;
};

PixelInputType FontVertexShader(VertexInputType input) {
  PixelInputType output;
    
  // Change the position vector to be 4 units for proper matrix calculations.
  input.position.w = 1.0f;

  // Calculate the position of the vertex against the world, view, and projection matrices.
  output.position = mul(input.position, worldMatrix);
  output.position = mul(output.position, viewMatrix);
  output.position = mul(output.position, projectionMatrix);
    
  // Store the texture coordinates for the pixel shader.
  output.tex = input.tex;
    
  return output;
}